A 3-dimensional structure semiconductor memory device including a memory hole and a silicon body on a substrate has been proposed. The memory hole is formed in a stacked body stacked with a plurality of electrode layers via insulating layers, and the silicon body serving as a channel is provided in the memory hole via a charge storage film. In such a semiconductor memory device, a memory cell including the charge storage film is formed at an intersection between the silicon body and the electrode layer. The electrode layer functions as a gate of the memory cell and forms a word line.
Recently, in such a semiconductor memory device, there is a tendency that high integration progresses miniaturization of elements in the semiconductor memory device, and the widths of both ends of the electrode layer are decreased. As the widths of both ends of the electrode layer are decreased, it is concerned that the resistivity of the electrode layer itself rises and a flow of a current is made harder to the electrode layer, thereby generating problems in the operation of the memory cell.